Does this look like an ordinary Google Map to you? Click the magnifier icon in top-left corner and see what happens! This feature was implemented with a mere two lines of code:

 <script src="GxMagnifier.1.js" type="text/javascript"></script>

and

 map.addControl(new GxMagnifierControl())

This is only the most basic example of what GxMagnifier can do. To learn more, check out the documentation.